The objective of this contract is to further the preclinical development of novel therapies (low molecular weigh organic molecules, biologics, and engineered viruses) for HIV- 1 through pre-clinical testing in the well characterized SCID-hu Thy/Liv modle small animal model. The major scientific functions of this contract are listed below: 1. Evaluate HIV therapeutics in an in vitro model 2. Evaluate potential HIV-1 therapeutics in vivo in a validated small-animal model 3. Maintain quality control/assurance of viral stocks, donor tissue, and reconstituted immunodeficient mice 4. Further characterize or develop the animal model and adapt newly discovered models 5. Collect samples of animal tissues and/or fluids and prepare such samples for shipment